Stone of Elucidation

 is an item in Tyranny.

Description
This sphere of dense stone packs the weight of a shield in the palm of your hand. Ancient runes cover the surface, each painted in chalky pigments that glow orange and violet in the dark.

Use

 * A Breach Between Worlds: Found at Blade Grave Oldwalls - Central in the upper left room, on the altar. Use a piece of rubble found nearby to weight the altar down to return.